Clinical Behavior in Metastatic Brain Disease Is Not Influenced by the Immunological Defense Mediated by CD57+NK-Cells

Objectives . The purpose of the present study is to verify if the degree of immunological response against metastatic tumors, measured by the number of CD57 + NK-cells in the tissue of a brain metastasis, influences the later development of new brain metastases or tumor recurrence. Patients and Methods . CD57 + NK-cells were immunohistochemically identified in the resected tumor, in a series of twenty patients operated on by a single brain metastasis secondary to lung adenocarcinoma. In each case, the degree of CD57 + NK-cells infiltration within the tumor tissue and the period free of new intracranial disease after brain surgery were recorded. Results . All the studied tumors showed variable number of CD57 + NK-cells (mean ± standard deviation: 8.4 ± 4.8 per microscopical field, at 200x). The period free of intracranial disease ranged between 10 and 52 weeks (mean ± standard deviation: 22.7 ± 11.9). Statistical analysis showed that there was no correlation between the degree of NK-cells infiltration within the resected tumor and the period free of intracranial disease after surgery ( P > 0.05). Conclusion . This finding supports that clinical behavior in metastatic brain disease is not influenced by the immunological response mediated by CD57 + NK-cells.